# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2011 Grid Dynamics
# Copyright 2011 OpenStack LLC.
# All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

import netaddr
import webob
from webob import exc

from nova.api.openstack import extensions
from nova.api.openstack import wsgi
from nova import exception
from nova import network
from nova.openstack.common import log as logging

LOG = logging.getLogger(__name__)
authorize = extensions.extension_authorizer('compute', 'networks')
authorize_view = extensions.extension_authorizer('compute', 'networks:view')


def network_dict(context, network):
    fields = ('id', 'cidr', 'netmask', 'gateway', 'broadcast', 'dns1', 'dns2',
              'cidr_v6', 'gateway_v6', 'label', 'netmask_v6')
    admin_fields = ('created_at', 'updated_at', 'deleted_at', 'deleted',
                    'injected', 'bridge', 'vlan', 'vpn_public_address',
                    'vpn_public_port', 'vpn_private_address', 'dhcp_start',
                    'project_id', 'host', 'bridge_interface', 'multi_host',
                    'priority', 'rxtx_base')
    if network:
        # NOTE(mnaser): We display a limited set of fields so users can know
        #               what networks are available, extra system-only fields
        #               are only visible if they are an admin.
        if context.is_admin:
            fields += admin_fields
        result = dict((field, network[field]) for field in fields)
        if 'uuid' in network:
            result['id'] = network['uuid']
        return result
    else:
        return {}


class NetworkController(wsgi.Controller):

    def __init__(self, network_api=None):
        self.network_api = network_api or network.API()

    def index(self, req):
        context = req.environ['nova.context']
        authorize_view(context)
        networks = self.network_api.get_all(context)
        result = [network_dict(context, net_ref) for net_ref in networks]
        return {'networks': result}

    @wsgi.action("disassociate")
    def _disassociate_host_and_project(self, req, id, body):
        context = req.environ['nova.context']
        authorize(context)
        LOG.debug(_("Disassociating network with id %s"), id)

        try:
            self.network_api.associate(context, id, host=None, project=None)
        except exception.NetworkNotFound:
            raise exc.HTTPNotFound(_("Network not found"))
        return exc.HTTPAccepted()

    def show(self, req, id):
        context = req.environ['nova.context']
        authorize_view(context)
        LOG.debug(_("Showing network with id %s") % id)
        try:
            network = self.network_api.get(context, id)
        except exception.NetworkNotFound:
            raise exc.HTTPNotFound(_("Network not found"))
        return {'network': network_dict(context, network)}

    def delete(self, req, id):
        context = req.environ['nova.context']
        authorize(context)
        LOG.info(_("Deleting network with id %s") % id)
        try:
            self.network_api.delete(context, id)
        except exception.NetworkNotFound:
            raise exc.HTTPNotFound(_("Network not found"))
        return exc.HTTPAccepted()

    def create(self, req, body):
        context = req.environ['nova.context']
        authorize(context)

        def bad(e):
            return exc.HTTPUnprocessableEntity(explanation=e)

        if not (body and body.get("network")):
            raise bad(_("Missing network in body"))

        params = body["network"]
        if not params.get("label"):
            raise bad(_("Network label is required"))

        cidr = params.get("cidr") or params.get("cidr_v6")
        if not cidr:
            raise bad(_("Network cidr or cidr_v6 is required"))

        LOG.debug(_("Creating network with label %s") % params["label"])

        params["num_networks"] = 1
        params["network_size"] = netaddr.IPNetwork(cidr).size

        network = self.network_api.create(context, **params)[0]
        return {"network": network_dict(context, network)}

    def add(self, req, body):
        context = req.environ['nova.context']
        authorize(context)
        if not body:
            raise exc.HTTPUnprocessableEntity()

        network_id = body.get('id', None)
        project_id = context.project_id
        LOG.debug(_("Associating network %(network)s"
                    " with project %(project)s") %
                  {"network": network_id or "",
                   "project": project_id})
        try:
            self.network_api.add_network_to_project(
                context, project_id, network_id)
        except Exception as ex:
            msg = (_("Cannot associate network %(network)s"
                     " with project %(project)s: %(message)s") %
                   {"network": network_id or "",
                    "project": project_id,
                    "message": getattr(ex, "value", str(ex))})
            raise exc.HTTPBadRequest(explanation=msg)

        return webob.Response(status_int=202)


class Networks(extensions.ExtensionDescriptor):
    """Admin-only Network Management Extension"""

    name = "Networks"
    alias = "os-networks"
    namespace = "http://docs.openstack.org/compute/ext/networks/api/v1.1"
    updated = "2011-12-23T00:00:00+00:00"

    def get_resources(self):
        member_actions = {'action': 'POST'}
        collection_actions = {'add': 'POST'}
        res = extensions.ResourceExtension(
            'os-networks',
            NetworkController(),
            member_actions=member_actions,
            collection_actions=collection_actions)
        return [res]
